Getting the best quality 4:3 image from 16:9 EX1R material

I've been rigorously doing some tests to get the best quality image from the EX1R for a 4:3 image. This is the process that i have finalised on:

1. Shooting with 'edge crop' and framing for a 4:3 image with masks as reference. (the masks are a reference only while shooting, generated by the camera, and do not show up once i transfer the material onto my computer).

2. once i import the material into fcp, i edit it and export the clip using quicktime conversion with the following settings:

the resultant image is a 4:3 image with the edges cropped. (i shot graph paper to determine the area it was cropping and it corresponds with the margins we made on the graph paper).

now the problem i'm facing is when i take up the issue of quality. the file i want to play back and project is an hour long. the material that we have has some critical exposures and highlights which are very integral for our work. after doing a series of tests on hd crt monitors and projectors, we figured that the uncompressed 10-bit codec works best for us. apple pro res 422 hq does some strange things with the colour and the contrast. the bummer bit about this is that the file is roughly 350gb in size! i'd have to get a really souped up machine to play back these files.

is there any other way to optimise my quality and not have such huge files? personally, i like the pro res codec. is there any other way of doing a better conversion of the ex1r material to pro res 422 hq?

I've often used my EX1 for SD delivery. I just use the XDCAM EX codec in an SD timeline. That gives me the flexibility to reposition shots, cut to closeups, build fake camera moves. I then export in ProRes.